Differential-pressure gage.



W. J. GROWELL, JR. DIFFERENTIAL PRESSURE GAGE. APPLICATION FILED AUG. 3, 1907.

' 314w M-foz WWI Patented Nov. 24, 1908 tl l ll l lill3 a DIFFERENTIAL-PRESSURE GAGE Qpecification of Letters Patent.

Patented Now-24, 1908.

Applicatiori and August ism. Serial No. 386,940.

To allwhom it may concern:

Be it known that I, VVILLIAM J. CaownLL, J12, a citizen of the United States, and a resident of the city of Lebanon, in the county of Lebanon and State of Pennsylvania, have invented certain new and useful Improvements in Diiferential-Pressure Gages, of which the following is a specification.

Myinvention relates to differential fluidpressure gages and it consists particularly in the improved construction and mounting of the U-tube as hereafter fully described, the novel features of which are specifically pointed out. in the claim.

The drawing is a diagrammatic view illustrating a preferred embodiment of the invention. v

In my improved gage the communicating U-tube columns A and B, to which the differential pressure is transmitted as usual through tubes C and D communicating with the two sources of pressure, are formed separately and are loosely connected together and to said tubes C and D so as to be capable of relative movement; this being accomplished as shown by employing flexible tubing E to afford communication between their lower ends, and flexible tubing F I to connect their upper ends to the tubes C D. These flexibly connected columns are mounted so as to have relative up and down movement imparted to them by the-differential pressuretransmitted through the tubes OD, while at the same time each is maintained in normal vertical position; this being accomplished as illustrated by pivotally suspending said columns upon knife-edges and h on opposite lateral arms G and II of "ross-shaped balance frame, which frame is pivotally mounted upon a suitably fixed knifeedge 70 arranged in a straight line with the column supporting knife-edges g and IL. This balance is also provided with a depending vertical arm J upon which is pivotally carried a suitable weight L which tends to maintain the swinging frame-in normal vertical position to which it is accurately adjusted by means of a movable regulating weight M on the lateral arm G. A pointer or recording pen N as usual is also carried by said swinging frame, for use in connection with any suitable scale as usual.

The varying differential pressure transmitted to the columns A and B from the connected sources of pressure, causes the locking liquid to be transferred from one column to the other as usual, thus correspondingly tilting the pivotally mounted frame and-moving the indicator N, as the heavier column falls and the lighter one rises. As the columns A and B are independently carried upon the respective knifeedges 9 and h, each column is free at all times to maintain av perfectly vertical position while thus producing a swinging movement of the balance frame as determined by the varying differential pressure and the returning action of the pivoted weight L, and the indications of differential pressure thus secured are uniformly reliable.

What I claim is An apparatus for indicating difference of pressure comprising separate U-tube columns having a flexible communicating connection at their lower ends and flexible communicatlag connection at their upper ends to dilferent sources; of pressure, supporting means for said tubes comprisinga pivotally mounted cross-shaped frame having oppositely extending lateral arms provided with pivotal supports for said tubes and a movable regulating weight, a depending rigid arm provided at its lower end with a pivotally mounted balance weight, and a verticallyrising rigid arm, and indicator means pivotally connected to said vertically rising arm substantially as set forth.

In testimony whereof, I afiix my signature, in the presence of two witnesses.

WILLIAM J. CROWELL, .lu.

' Witnesses I). M. STEWART, W. G. STEWART. 

